ABSTRACT
Dosimetry modeling and point of departure (POD) estimation using in vitro data are essential for mechanism-based hazard identification and risk assessment. This study aimed to develop a putative adverse outcome pathway (AOP) for humidifier disinfectant (HD) substances used in South Korea through a systematic review and benchmark dose (BMD) modeling. We collected in vitro toxicological studies on HD substances, including polyhexamethylene guanidine hydrochloride (PHMG-HCl), PHMG phosphate (PHMG-p), a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (CMIT/MIT), CMIT, and MIT from scientific databases. A total of 193 sets of dose-response data were extracted from 34 articles reporting in vitro experimental results of HD toxicity. The risk of bias (RoB) in each study was assessed following the office of health assessment and translation (OHAT) guideline. The BMD of each HD substance at different toxicity endpoints was estimated using the US Environmental Protection Agency (EPA) BMD software (BMDS). Interspecies- or interorgan differences or most critical effects in the toxicity of the HD substances were analyzed using a 95% lower confidence limit of the BMD (BMDL). We found a critical molecular event and cells susceptible to each HD substance and constructed an AOP of PHMG-p- or CMIT/MIT-induced damage. Notably, PHMG-p induced ATP depletion at the lowest in vitro concentration, endoplasmic reticulum (ER) stress, epithelial-to-mesenchymal transition (EMT), inflammation, leading to fibrosis. CMIT/MIT enhanced mitochondrial reactive oxygen species (ROS) production, oxidative stress, mitochondrial dysfunction, resulting in cell death. Our approach will increase the current understanding of the effects of HD substances on human health and contribute to evidence-based risk assessment of these compounds.
ABSTRACT
BACKGROUND: Titanium dioxide nanoparticles (TiO2NPs) are widely used in medical application. However, the relevant health risk has not been completely assessed, the potential of inducing arterial thrombosis (AT) in particular. METHODS: Alterations in platelet function and susceptibility to arterial thrombosis induced by TiO2NPs were examined using peripheral blood samples from healthy adult males and an in vivo mouse model, respectively. RESULTS: Here, using human platelets (hPLTs) freshly isolated from health volunteers, we demonstrated TiO2NP treatment triggered the procoagulant activity of hPLTs through phosphatidylserine exposure and microvesicles generation. In addition, TiO2NP treatment increased the levels of glycoprotein IIb/IIIa and P-selectin leading to aggregation and activation of hPLTs, which were exacerbated by providing physiology-mimicking conditions, including introduction of thrombin, collagen, and high shear stress. Interestingly, intracellular calcium levels in hPLTs were increased upon TiO2NP treatment, which were crucial in TiO2NP-induced hPLT procoagulant activity, activation and aggregation. Moreover, using mice in vivo models, we further confirmed that TiO2NP treatment a reduction in mouse platelet (mPLT) counts, disrupted blood flow, and exacerbated carotid arterial thrombosis with enhanced deposition of mPLT. CONCLUSIONS: Together, our study provides evidence for an ignored health risk caused by TiO2NPs, specifically TiO2NP treatment augments procoagulant activity, activation and aggregation of PLTs via calcium-dependent mechanism and thus increases the risk of AT.
Subject(s)
Blood Platelets , Platelet Activation , Platelet Aggregation , Thrombosis , Titanium , Titanium/toxicity , Animals , Humans , Platelet Aggregation/drug effects , Blood Platelets/drug effects , Blood Platelets/metabolism , Male , Thrombosis/chemically induced , Mice , Platelet Activation/drug effects , Adult , Platelet Glycoprotein GPIIb-IIIa Complex/metabolism , Blood Coagulation/drug effects , Mice, Inbred C57BL , P-Selectin/metabolism , Calcium/metabolism , Calcium/blood , Nanoparticles/toxicity , Metal Nanoparticles/toxicityABSTRACT
Air pollution has recently emerged as a significant risk factor for ischemic stroke. Although there is a robust association between higher concentrations of ambient particulate matter (PM2.5) and increased incidence and mortality rates of ischemic stroke, the precise mechanisms underlying PM2.5-induced ischemic stroke remain to be fully elucidated. The purpose of this study was to examine the synergistic effect of PM2.5 and hypoxic stress using in vivo and in vitro ischemic stroke models. Intravenously administered PM2.5 exacerbated the ischemic brain damage induced by middle cerebral artery occlusion (MCAo) in Sprague Dawley rats. Alterations in autophagy flux and decreased levels of tight junction proteins were observed in the brain of PM2.5-administered rats after MCAo. The underlying mechanism of PM2.5-induced potentiation of ischemic brain damage was investigated in neurons, perivascular macrophages, and brain endothelial cells, which are the major components of the integrated neurovascular unit. Co-treatment with PM2.5 and oxygen-glucose deprivation (OGD) amplified the effects of OGD on the reduction of viability in primary neurons, immortalized murine hippocampal neuron (HT-22), and brain endothelial cells (bEND.3). After co-treatment with PM2.5 and OGD, the Akt/ß-catenin and autophagy flux were significantly inhibited in HT-22 cells. Notably, the protein levels of metalloproteinase-9 and cystatin C were elevated in the conditioned media of murine macrophages (RAW264.7) exposed to PM2.5, and tight junction protein expression was significantly decreased after OGD exposure in bEND.3 cells pretreated with the conditioned media. Our findings suggest that perivascular macrophages may mediate PM2.5-induced brain endothelial dysfunction following ischemia and that PM2.5 can exacerbate ischemia-induced neurovascular damage. © 2017 Elsevier Inc. All rights reserved.
ABSTRACT
Dodecamethylcyclohexasiloxane (D6) is a siloxane substance mainly used in cosmetics and personal care products. While octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) were once commonly used in personal care products, their usage has been restricted due to the classification as persistent, bioaccumulative, and toxic (PBT)/very persistent and very bio-accumulative (vPvB) substances. While D6 has emerged as a substitute for D4 and D5, the risk assessment for D6 remains limited compared to the evaluations for D4 and D5. To address this gap, we conducted a comprehensive risk assessment of D6. In this study, we reviewed the toxicity information on D6 and calculated the exposure level to D6, considering the content of D6 in cosmetic products. No observed adverse effect level (NOAEL) of 1500 mg/kg bw/day was established in a repeated dose toxicity study after oral administration to rats. Negative results were found in tests on the ocular and skin irritation, skin sensitization, and genotoxicity of D6. According to the product content of up to 48% of D6 reported in 2012, the Systemic Exposure Dose (SED) was 5.4E-06 to 7.04 mg/kg bw/day for a 60 kg adult using the exposure factors from Korean cosmetic usage. The Margin of Safety was estimated to be between 35.5 and 4.63E+07, posing a potential health risk of D6 according to the maximum concentration and the product type. Further consideration of the potential of D6 as PBT or vPvB is also required.
ABSTRACT
Cocamidopropyl betaine (CAPB) is a surfactant derived from coconut oil that is widely used in cosmetics and personal products for several purposes, such as a surfactant, foam booster, mildness, and viscosity control. Cocamidopropyl betaine is used at concentrations up to 30% in cosmetics. The acute toxicity, skin irritation, eye irritation, skin sensitization, repeated dose toxicity, genotoxicity, carcinogenicity, and phototoxicity of cocamidopropyl betaine were evaluated. Cocamidopropyl betaine was observed to induce mild skin irritation, eye irritation and skin sensitization. The NOAEL of cocamidopropyl betaine was determined to be 250 mg/kg/day based on the results of a 92-day repeated-dose oral toxicity study in rats. The systemic exposure dose of cocamidopropyl betaine was estimated to range from 0.00120 to 0.93195 mg/kg/day when used in cosmetic products. The margin of safety of cocamidopropyl betaine was calculated to be greater than 100 when used at a maximum concentration of 6% in leave-on products and 30% in rinse-off products, suggesting that its use in cosmetic products is safe under current usage conditions.
ABSTRACT
Cardiac organoids have emerged as invaluable tools for assessing the impact of diverse substances on heart function. This report introduces guidelines for general requirements for manufacturing cardiac organoids and conducting cardiac organoid-based assays, encompassing protocols, analytical methodologies, and ethical considerations. In the quest to employ recently developed three-dimensional cardiac organoid models as substitutes for animal testing, it becomes imperative to establish robust criteria for evaluating organoid quality and conducting toxicity assessments. This guideline addresses this need, catering to regulatory requirements, and describes common standards for organoid quality and toxicity assessment methodologies, commensurate with current technological capabilities. While acknowledging the dynamic nature of technological progress and the potential for future comparative studies, this guideline serves as a foundational framework. It offers a comprehensive approach to standardized cardiac organoid testing, ensuring scientific rigor, reproducibility, and ethical integrity in investigations of cardiotoxicity, particularly through the utilization of human pluripotent stem cell-derived cardiac organoids.
ABSTRACT
Growing concerns exist about increasing chemical usage and the potential health risks. Developing an efficient strategy to evaluate or predict the toxicity of chemicals is necessary. The mitochondria are essential organelles for cell maintenance and survival but also serve as one of the main targets of toxic chemicals. Mitochondria play an important role in the pathology of respiratory disease, and many environmental chemicals may induce impairment of the respiratory system through mitochondrial damage. This study aimed to develop integrated in vitro approaches to identify chemicals that could induce adverse health effects by increasing mitochondria-mediated oxidative stress using the H441 cells, which have a club-cell-like phenotype. Twenty-six environmental toxicants (biocides, phthalates, bisphenols, and particles) were tested, and each parameter was compared with eleven reference compounds. The inhibitory concentrations (IC20 and IC50) and benchmark doses (BMD) of the tested compounds were estimated from three in vitro assays, and the toxic concentration was determined. At the lowest IC20, the effects of compounds on mitochondrial reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) were compared. Principal component analysis and k-mean clustering were performed to cluster the chemicals that had comparable effects on the cells. Chemicals that induce mitochondrial damage at different concentrations were used for an in-depth high-tier assessment and classification as electron transport system (ETS) uncoupling or inhibiting agents. Additionally, using in vitro to in vivo extrapolation (IVIVE) tools, equivalent administration doses and maximum plasma concentrations of tested compounds in human were estimated. This study suggests an in vitro approach to identifying mitochondrial damage by integrating several in vitro toxicity tests and calculation modeling.
Subject(s)
Hazardous Substances , Mitochondria , Humans , Mitochondria/metabolism , Hazardous Substances/toxicity , Electron Transport , Oxidative Stress , Reactive Oxygen Species/metabolismABSTRACT
Parabens are widely used as preservatives, added to products commonly used by humans, and to which individuals are exposed orally or dermally. Once absorbed into the body, parabens move into the bloodstream and travel through the systemic circulation. We investigated the potential impact of parabens on the enhanced generation of thrombin by red blood cells (RBCs), which are the principal cellular components of blood. We tested the effects of methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP), and p-hydroxybenzoic acid on freshly isolated human RBCs. BuP and simultaneous exposure to BuP and PrP significantly increased phosphatidylserine (PS) externalization to the outer membranes of RBCs. PS externalization by BuP was found to be mediated by increasing intracellular Ca2+ levels in RBCs. The morphological changes in BuP-treated RBCs were observed under an electron microscope. The BuP-exposed RBCs showed increased thrombin generation and adhesion to endothelial cells. Additionally, the externalization of PS exposure and thrombin generation in BuP-treated RBCs were more susceptible to high shear stress, which mimics blood turbulence under pathological conditions. Collectively, we observed that BuP induced morphological and functional changes in RBCs, especially under high shear stress, suggesting that BuP may contribute to the thrombotic risk via procoagulant activity in RBCs.
Subject(s)
Parabens , Phosphatidylserines , Humans , Parabens/toxicity , Calcium/pharmacology , Thrombin/pharmacology , Endothelial Cells , ErythrocytesABSTRACT
Phthalates in contaminated foods and personal care products are one of the most frequently exposed chemicals with a public health concern. Phthalate exposure is related to cardiovascular diseases, including diabetic vascular complications and cerebrovascular diseases, yet the mechanism is still unclear. The blood-brain barrier (BBB) integrity disruption is strongly associated with cardiovascular and neurological disease exacerbation. We investigated BBB damage by di-(2-ethylhexyl) phthalate (DEHP) or its metabolite mono-(2-ethylhexyl) phthalate (MEHP) using brain endothelial cells and rat models. BBB damage by the subthreshold level of MEHP, but not a DEHP, significantly increased by the presence of methylglyoxal (MG), a reactive dicarbonyl compound whose levels increase in the blood in hyperglycemic conditions in diabetic patients. Significant potentiation in apoptosis and autophagy activation, mitochondria-derived reactive oxygen species (ROS) production, and mitochondrial metabolic disturbance were observed in brain ECs by co-exposure to MG and MEHP. N-acetyl cysteine (NAC) restored autophagy activation as well as tight junction protein impairment induced by co-exposure to MG and MEHP. Intraperitoneal administration of MG and MEHP significantly altered mitochondrial membrane potential and tight junction integrity in rat brain endothelium. This study may provide novel insights into enhancing phthalate toxicity in susceptible populations, such as diabetic patients.
Subject(s)
Diethylhexyl Phthalate , Rats , Animals , Diethylhexyl Phthalate/toxicity , Pyruvaldehyde , Blood-Brain Barrier/metabolism , Endothelial Cells/metabolism , Oxidative Stress , Energy Metabolism , Mitochondria/metabolismABSTRACT
The gut microbiota affects hepatic drug metabolism. However, gut microbial factors modulating hepatic drug metabolism are largely unknown. In this study, using a mouse model of acetaminophen (APAP)-induced hepatotoxicity, we identified a gut bacterial metabolite that controls the hepatic expression of CYP2E1 that catalyzes the conversion of APAP to a reactive, toxic metabolite. By comparing C57BL/6 substrain mice from two different vendors, Jackson (6J) and Taconic (6N), which are genetically similar but harbor different gut microbiotas, we established that the differences in the gut microbiotas result in differential susceptibility to APAP-induced hepatotoxicity. 6J mice exhibited lower susceptibility to APAP-induced hepatotoxicity than 6N mice, and such phenotypic difference was recapitulated in germ-free mice by microbiota transplantation. Comparative untargeted metabolomic analysis of portal vein sera and liver tissues between conventional and conventionalized 6J and 6N mice led to the identification of phenylpropionic acid (PPA), the levels of which were higher in 6J mice. PPA supplementation alleviated APAP-induced hepatotoxicity in 6N mice by lowering hepatic CYP2E1 levels. Moreover, PPA supplementation also reduced carbon tetrachloride-induced liver injury mediated by CYP2E1. Our data showed that previously known PPA biosynthetic pathway is responsible for PPA production. Surprisingly, while PPA in 6N mouse cecum contents is almost undetectable, 6N cecal microbiota produces PPA as well as 6J cecal microbiota in vitro, suggesting that PPA production in the 6N gut microbiota is suppressed in vivo. However, previously known gut bacteria harboring the PPA biosynthetic pathway were not detected in either 6J or 6N microbiota, suggesting the presence of as-yet-unidentified PPA-producing gut microbes. Collectively, our study reveals a novel biological function of the gut bacterial metabolite PPA in the gut-liver axis and presents a critical basis for investigating PPA as a modulator of CYP2E1-mediated liver injury and metabolic diseases.
Subject(s)
Chemical and Drug Induced Liver Injury , Gastrointestinal Microbiome , Mice , Animals , Mice, Inbred C57BL , Acetaminophen/toxicity , Cytochrome P-450 CYP2E1/geneticsABSTRACT
The pharmacological or toxicological activities of the degradation products of drug candidates have been unaddressed during the drug development process. Ischemic stroke accounts for 80% of all strokes and is responsible for considerable mortality and disability worldwide. Despite decades of research on neuroprotective agents, tissue plasminogen activators (t-PA), a thrombolytic agent, remains the only approved acute stroke pharmacological therapy. NXY-059, a free radical scavenger, exhibited striking neuroprotective properties in preclinical models and met all the criteria established by the Stroke Academic Industry Roundtable (STAIR) for a neuroprotective agent. In phase 3 clinical trials, NXY-059 exhibited significant neuroprotective effects in one trial (SAINT-I), but not in the second (SAINT-II). Some have hypothesized that N-t-butyl hydroxylamine (NtBHA), a breakdown product of NXY-059 was the actual neuroprotective agent in SAINT-I and that changes to the formulation of NXY-059 to prevent its breakdown to NtBHA in SAINT -II was the reason for the lack of efficacy. We evaluated the neuroprotective effect of NtBHA in N-methyl-D-aspartate (NMDA)-treated primary neurons and in rat focal cerebral ischemia. NtBHA significantly attenuated infarct volume in rat transient focal ischemia, and attenuated NMDA-induced cytotoxicity in primary cortical neurons. NtBHA also reduced free radical generation and exhibited mitochondrial protection.
ABSTRACT
BACKGROUND: Microplastics (MPs) and nanoplastics (NPs) formed from decomposed plastic are increasing environmental threats. Although MPs and NPs exposed through various routes enter the systemic circulation, the potential toxicity of those is largely unknown. We investigated whether polystyrene NPs (PS-NPs) promote the coagulation activity of red blood cells (RBCs). RESULTS: We tested several types of PS-NPs using human RBCs and found that amine-modified 100 nm PS-NPs were the most potent. We measured the uptake of PS-NPs using flow cytometry and confocal microscopy. Electron microscopy revealed morphological changes of RBCs by PS-NPs. PS-NPs induced the externalization of phosphatidylserine, generation of microvesicles in RBCs, and perturbations in the intracellular microenvironment. PS-NPs increased the activity of scramblases responsible for phospholipid translocation in RBCs. PS-NPs modulated the functional interaction to adjacent tissues and coagulation cascade, enhancing RBC adhesion and thrombin generation. Our observations in human RBCs were consistent with those in isolated rat RBCs, showing no inter-species differences. In rat venous thrombosis models, the intravenous administration of PS-NPs enhanced thrombus formation. CONCLUSION: Amine-modified PS-NPs induce the prothrombotic activation of RBCs causing thrombus formation. We believe that our study will contribute to understanding the potential toxicity of amine-modified polystyrene particles in blood cells and cardiovascular systems.
Subject(s)
Microplastics , Thrombosis , Amines , Animals , Erythrocytes , Humans , Plastics , Polystyrenes/toxicity , RatsABSTRACT
The mixture of 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT, chloromethylisothiazolinone) and 2-methyl-4-isothiazolin-3-one (MIT, methylisothiazolinone) is a commonly used biocide in consumer products. Despite the health issues related to its usage in cosmetics and humidifier disinfectants (HD), understanding its adverse outcome is still limited. Using in vitro cell lines and ex vivo rat models, we examined the effects of CMIT/MIT on the cellular redox homeostasis and energy metabolism in the brain microvascular endothelium, a highly restrictive interface between the bloodstream and brain. In murine bEND.3 and human hCMEC/D3, CMIT/MIT significantly amplified the mitochondrial-derived oxidative stress causing disruption of the mitochondrial membrane potential and oxidative phosphorylation at a sub-lethal concentration (1 µg/mL) or treatment duration (1 h). In addition, CMIT/MIT significantly increased a dynamic imbalance between mitochondrial fission and fusion, and endogenous pathological stressors significantly potentiated the CMIT/MIT-induced endothelial dysfunction. Notably, in the brain endothelium isolated from intravenously CMIT/MIT-administered rats, we observed significant mitochondrial damage and decreased tight junction protein. Taken together, we report that CMIT/MIT significantly impaired mitochondrial function and dynamics resulting in endothelial barrier dysfunction, giving an insight into the role of mitochondrial damage in CMIT/MIT-associated systemic health effects.
Subject(s)
Disinfectants , Animals , Brain , Cell Line , Disinfectants/toxicity , Endothelial Cells , Endothelium , Humans , Mice , Rats , ThiazolesABSTRACT
Acute kidney injury (AKI) is a serious threat to human health. Clinically, ischemia-reperfusion (I/R) injury is considered one of the most common contributors to AKI. Emodin has been reported to alleviate I/R injury in the heart, brain, and small intestine in rats and mice through its anti-inflammatory effects. The present study investigated whether emodin improved AKI induced by I/R and elucidated the molecular mechanisms. We used a mouse model of renal I/R injury and human renal tubular epithelial cell model of hypoxia/reoxygenation (H/R) injury. Ischemia/reperfusion resulted in renal dysfunction. Pretreatment with emodin ameliorated renal injury in mice following I/R injury. Emodin reduced mitochondrial-mediated apoptosis, suppressed the overproduction of mitochondrial reactive oxygen species and accelerated the recovery of adenosine triphosphate both in vivo and in vitro. Emodin prevented mitochondrial fission and restored the balance of mitochondrial dynamics. The phosphorylation of dynamin-related protein 1 (DRP1) at Ser616, a master regulator of mitochondrial fission, was upregulated in both models of I/R and H/R injury, and this upregulation was blocked by emodin. Using computational cognate protein kinase prediction and specific kinase inhibitors, we found that emodin inhibited the phosphorylation of calcium/calmodulin-dependent protein kinase II (https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=1554), thereby inhibiting its kinase activity and reducing the phosphorylation of DRP1 at Ser616. The results demonstrated that emodin pretreatment could protect renal function by improving mitochondrial dysfunction induced by I/R.
Subject(s)
Acute Kidney Injury/prevention & control , Calcium-Calmodulin-Dependent Protein Kinase Type 2/antagonists & inhibitors , Dynamins/antagonists & inhibitors , Emodin/pharmacology , Mitochondrial Dynamics/drug effects , Protective Agents/pharmacology , Reperfusion Injury/prevention & control , Acute Kidney Injury/pathology , Animals , Apoptosis/drug effects , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Cell Line , Disease Models, Animal , Dynamins/metabolism , Emodin/therapeutic use , Humans , Male , Mice, Inbred C57BL , Mitochondria/drug effects , Oxidative Stress/drug effects , Phosphorylation/drug effects , Protective Agents/therapeutic use , Reperfusion Injury/pathologyABSTRACT
BACKGROUND: Expanding biomedical application of anatase titanium dioxide (TiO2) nanoparticles (NPs) is raising the public concern on its potential health hazards. Here, we demonstrated that TiO2 NPs can increase phosphatidylserine (PS) exposure and procoagulant activity of red blood cells (RBCs), which may contribute to thrombosis. RESULTS: We conducted in vitro studies using RBCs freshly isolated from healthy male volunteers. TiO2 NPs exposure (⦠25 µg/mL) induced PS exposure and microvesicles (MV) generation accompanied by morphological changes of RBCs. While ROS generation was not observed following the exposure to TiO2 NPs, intracellular calcium increased and caspase-3 was activated, which up-regulated scramblase activity, leading to PS exposure. RBCs exposed to TiO2 NPs could increase procoagulant activity as measured by accelerated thrombin generation, and enhancement of RBC-endothelial cells adhesion and RBC-RBC aggregation. Confirming the procoagulant activation of RBC in vitro, exposure to TiO2 NPs (2 mg/kg intravenously injection) in rats increased thrombus formation in the venous thrombosis model. CONCLUSION: Collectively, these results suggest that anatase TiO2 NPs may harbor prothrombotic risks by promoting the procoagulant activity of RBCs, which needs attention for its biomedical application.
Subject(s)
Nanoparticles , Thrombosis , Animals , Endothelial Cells , Erythrocytes , Male , Nanoparticles/toxicity , Phosphatidylserines , Rats , Thrombosis/chemically induced , Titanium/toxicityABSTRACT
Isothiazolinone (IT) biocides are potent antibacterial substances used as preservatives and disinfectants. These biocides exert differing biocidal effects and display environmental stability based upon chemical structure. In agreement with our recent study reporting that 2-n-octyl-4-isothiazolin-3-one (OIT) induced dysfunction of the blood-brain barrier (BBB), the potential adverse health effects of two IT biocides 1,2-benzisothiazolin-3-one (BIT) and 4,5-dichloro-2-n-octyl-isothiazolin-3-one (DCOIT) were compared using brain endothelial cells (ECs) derived from murine brain endothelial cell line (bEND.3). BIT possesses an unchlorinated IT ring structure and used as a preservative in cleaning products. DCOIT contains a chlorinated IT ring structure and employed as an antifouling agent in paints. Data demonstrated that DCOIT altered cellular metabolism at a lower concentration than BIT. Both BIT and DCOIT increased reactive oxygen species (ROS) generation at the mitochondrial and cellular levels. However, the effect of DCOIT on glutathione (GSH) levels appeared to be greater than BIT. While mitochondrial membrane potential (MMP) was decreased in both BIT- and DCOIT-exposed cells, direct disturbance in mitochondrial bioenergetic flux was only observed in BIT-treated ECs. Taken together, IT biocides produced toxicity in brain EC and barrier dysfunction, but at different concentration ranges suggesting distinct differing mechanisms related to chemical structure.
Subject(s)
Blood-Brain Barrier/drug effects , Disinfectants/toxicity , Mitochondria/drug effects , Thiazoles/toxicity , Animals , Blood-Brain Barrier/metabolism , Cell Line , Disinfectants/chemistry , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Energy Metabolism/drug effects , Glutathione/metabolism , Membrane Potential, Mitochondrial/drug effects , Mice , Mitochondria/metabolism , Oxygen Consumption/drug effects , Reactive Oxygen Species/metabolism , Thiazoles/chemistryABSTRACT
Stroke is one of the leading causes of death and disability worldwide. However, treatment options for ischemic stroke remain limited. Matrix-metalloproteinases (MMPs) contribute to brain damage during ischemic strokes by disrupting the blood-brain barrier (BBB) and causing brain edemas. Carnosine, an endogenous dipeptide, was found by us and others to be protective against ischemic brain injury. In this study, we investigated whether carnosine influences MMP activity. Brain MMP levels and activity were measured by gelatin zymography after permanent occlusion of the middle cerebral artery (pMCAO) in rats and in vitro enzyme assays. Carnosine significantly reduced infarct volume and edema. Gelatin zymography and in vitro enzyme assays showed that carnosine inhibited brain MMPs. We showed that carnosine inhibited both MMP-2 and MMP-9 activity by chelating zinc. Carnosine also reduced the ischemia-mediated degradation of the tight junction proteins that comprise the BBB. In summary, our findings show that carnosine inhibits MMP activity by chelating zinc, an essential MMP co-factor, resulting in the reduction of edema and brain injury. We believe that our findings shed new light on the neuroprotective mechanism of carnosine against ischemic brain damage.
Subject(s)
Brain Ischemia/drug therapy , Carnosine/pharmacology , Infarction, Middle Cerebral Artery/complications , Matrix Metalloproteinase 2/chemistry , Matrix Metalloproteinase 9/chemistry , Matrix Metalloproteinase Inhibitors/pharmacology , Reperfusion Injury/drug therapy , Animals , Brain Ischemia/enzymology , Brain Ischemia/etiology , Brain Ischemia/pathology , Female , Rats , Rats, Sprague-Dawley , Reperfusion Injury/enzymology , Reperfusion Injury/etiology , Reperfusion Injury/pathologyABSTRACT
Isothiazolinone (IT) biocides are potent antibacterial substances commonly used as preservatives or disinfectants, and 2-n-Octyl-4-isothiazolin-3-one (OIT; octhilinone) is a common IT biocide that is present in leather products, glue, paints, and cleaning products. Although humans are exposed to OIT through personal and industrial use, the potentially deleterious effects of OIT on human health are still unknown. To investigate the effects of OIT on the vascular system, which is continuously exposed to xenobiotics through systemic circulation, we treated brain endothelial cells with OIT. OIT treatment significantly activated caspase-3-mediated apoptosis and reduced the bioenergetic function of mitochondria in a bEnd.3 cell-based in vitro blood-brain barrier (BBB) model. Interestingly, OIT significantly altered the thiol redox status, as evidenced by reduced glutathione levels and protein S-nitrosylation. The endothelial barrier function of bEnd.3 cells was significantly impaired by OIT treatment. OIT affected mitochondrial dynamics through mitophagy and altered mitochondrial morphology in bEnd.3 cells. N-acetyl cysteine significantly reversed the effects of OIT on the metabolic capacity and endothelial function of bEnd.3 cells. Taken together, we demonstrated that the alteration of the thiol redox status and mitochondrial damage contributed to OIT-induced BBB dysfunction, and we hope that our findings will improve our understanding of the potential hazardous health effects of IT biocides.
Subject(s)
Blood-Brain Barrier/drug effects , Blood-Brain Barrier/metabolism , Disinfectants/toxicity , Thiazoles/toxicity , Acetylcysteine/pharmacology , Animals , Antioxidants/pharmacology , Blood-Brain Barrier/pathology , Brain/drug effects , Brain/metabolism , Brain/pathology , Cell Death/drug effects , Cell Line , Disinfectants/antagonists & inhibitors , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Endothelial Cells/pathology , Energy Metabolism/drug effects , Humans , Membrane Potential, Mitochondrial/drug effects , Mice , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/pathology , Proteolysis/drug effects , Reactive Oxygen Species/metabolism , Sulfhydryl Compounds/metabolism , Thiazoles/antagonists & inhibitors , Tight Junction Proteins/metabolismABSTRACT
During the past two decades, the clinical use of biopharmaceutical products has markedly increased because of their obvious advantages over conventional small-molecule drug products. These advantages include better specificity, potency, targeting abilities, and reduced side effects. Despite the substantial clinical and commercial success, the macromolecular structure and intrinsic instability of biopharmaceuticals make their formulation and administration challenging and render parenteral delivery as the only viable option in most cases. The use of nanocarriers for efficient delivery of biopharmaceuticals is essential due to their practical benefits such as protecting from degradation in a hostile physiological environment, enhancing plasma half-life and retention time, facilitating absorption through the epithelium, providing site-specific delivery, and improving access to intracellular targets. In the current review, we highlight the clinical and commercial success of biopharmaceuticals and the overall applications and potential of nanocarriers in biopharmaceuticals delivery. Effective applications of nanocarriers for biopharmaceuticals delivery via invasive and noninvasive routes (oral, pulmonary, nasal, and skin) are presented here. The presented data undoubtedly demonstrate the great potential of combining nanocarriers with biopharmaceuticals to improve healthcare products in the future clinical landscape. In conclusion, nanocarriers are promising delivery tool for the hormones, cytokines, nucleic acids, vaccines, antibodies, enzymes, and gene- and cell-based therapeutics for the treatment of multiple pathological conditions.
ABSTRACT
The short release half-life of carbon monoxide (CO) is a major obstacle to the effective therapeutic use of carbon monoxide-releasing molecule-2 (CORM-2). The potential of CORM-2-entrapped ultradeformable liposomes (CORM-2-UDLs) to enhance the release half-life of CO and alleviate skin inflammation was investigated in the present study. CORM-2-UDLs were prepared by using soy phosphatidylcholine to form lipid bilayers and Tween 80 as an edge activator. The deformability of CORM-2-UDLs was measured and compared with that of conventional liposomes by passing formulations through a filter device at a constant pressure. The release profile of CO from CORM-2-UDLs was evaluated by myoglobin assay. In vitro and in vivo anti-inflammatory effects of CORM-2-UDLs were assessed in lipopolysaccharide-stimulated macrophages and TPA-induced ear edema model, respectively. The deformability of the optimized CORM-2-UDLs was 2.3 times higher than conventional liposomes. CORM-2-UDLs significantly prolonged the release half-life of CO from 30 s in a CORM-2 solution to 21.6 min. CORM-2-UDLs demonstrated in vitro anti-inflammatory activity by decreasing nitrite production and pro-inflammatory cytokine levels. Furthermore, CORM-2-UDLs successfully ameliorated skin inflammation by reducing ear edema, pathological scores, neutrophil accumulation, and inflammatory cytokines expression. The results demonstrate that CORM-2-UDLs could be used as promising therapeutics against acute skin inflammation.